Loosen or Remove Stripped Screw Q&A

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Dear NH,

I don't know if you can help. I used my husband's electric drill today to
attempt to remove four screws in hot tub (yes, I am in California) maintenance
panel. The maintenance fellow recently repaired the hot tub and apparently
improperly put in last screw. Probably used his drill. When I came to the
troublesome screw (had tried earlier to unscrew it with a long screwdriver), the
drill just stripped the head so no way I can get a Phillips screwdriver to fit
in properly.

Is there any trick to removing a screw with stripped head? My husband is not
the handy type, nor is he patient. Have learned, after 37 years, that it is
better if I tackle these jobs myself.

P

Dear P,

There are three methods of screw extraction when the screw heads are hopelessly
damaged.

(1) The first is to just use an electric drill to remove the head of the
screw. Drill directly through the center of the head with a drill bit about 1/3 the size of the
screw's head, about 1/8" deep. Use progressively larger bits
until the head of the screw comes off. Then, remove the maintenance panel. There
should be more than enough screw shank (the "body" of the screw)
remaining to grip with a pair of pliers... preferable self locking pliers such
as Vice Grips. Hold tight and carefully turn the screw out.

(2) If course, if the panel you are removing is very thin, there might not be
enough screw shank to grip… so you can use a screw extractor instead. A screw
extractor looks something like a blunt-ended screw with very broad threads.
These hardened cutting threads are in the opposite direction of a standard
right-hand threaded screw. When you turn the extractor, it tightens into the
hole giving it a firm grip. To get a correctly sized screw extractor, take one
of the screws you successfully removed to the hardware store. The salesman
should be able to give you the correct size extractor and the right size drill
bit for this job! The hole size is important… it should be no more than about
75% of the diameter of the screw shank. If you attempt to use too large an
extractor by drilling too large a hole you may overly weaken the screw shank and
the head might just break off! Back to step one!

To remove the screw, drill into the damaged screw head about 1/8-1/4 inch
deep. Push the extractor into the hole and rotate it counterclockwise with
pliers or a Vise Grips to remove the screw.

(3) There is another possible way to get the screw out that is a little less
laborious but has a lower success rate, especially if the screw is really jammed
into place. Instead of trying to remove the screw with a Phillips screwdriver,
try using a square-drive bit instead. Square-drive bits are designed to be used
with a special type of screw used in both construction and cabinetmaking. The
head of the screw has a deep square moulded into it. This design gives
tremendous gripping power to the bit and is more difficult to strip.

Anyway, sometimes it is possible to tap a square-drive bit into a damaged
Phillips screw head and get just enough grip to extract it! If you don't have a
screwdriver with replaceable tips (everyone should have one), you can get one at
the hardware store… plus an assortment of square drive bits to go with it!